W07 Wing box - Left Hand Wing - I returned the root rib to its position. I drilled the pilot holes for the upper and lower aft skins into the aft root rib. I drilled all the remaining pilot holes for the main spar for both upper and lower aft skins. I up drilled to #30 holes for the lower aft skin except for both main and rear spars and the root doubler / wing walk. I unpacked the leading edge skin and clecoed it inplace at the upper main spar.

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